| 摘要 |
PURPOSE: A fabrication method of an EEPROM is provided to improve a programmable efficiency by increasing a coupling ratio. CONSTITUTION: A plurality of first floating gates(203) having constant distance are formed on a substrate(201) having a tunneling oxide(202). An oxide sidewalls(205) is formed at both sidewalls of the first floating gates. After forming source/drain regions(206,207) in the substrate, a thermal oxide(208) is formed on the substrate. After forming an insulating layer(209) on the resultant structure, the surface of the first floating gates(203) is partially exposed by selectively etching the insulating layer(209). Second floating gates(210) are formed on the exposed first floating gates. A dielectric film(211) is formed on the second floating gates. A control gate(212) is formed on the dielectric film and spaced apart from the vertical direction of the first and second floating gates.
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